论文部分内容阅读
针对随机介质模型和组合震源模型，应用二维网络系统有限元数值模拟方法，研究了微震的空间和时间分布序列及震级－频度关系。结果表明，微震从起初随机无序的空间分布状态逐渐向临震前主震源区域集中，呈现有序分布迁移，前兆具有“先外围，后震中”的传播特征。此外，震级－频度的线性关系只近似存在于中等震级范围内，对于高震级与低震级都有很大的偏移
For the random media model and the combined source model, the two-dimensional network system finite element method is used to study the spatial and temporal distribution sequence and magnitude-frequency relationship of microseism. The results show that the microseism gradually migrates from the initial random disordered spatial distribution to the main source region before the quake, showing an orderly distribution and migration. The precursor has the characteristics of “pre-epicenter and post-epicenter”. In addition, the linear relationship between magnitude and frequency is only approximately in the middle magnitude range, with a large offset for both high and low magnitudes